Interest in electronic and computerized implementations of casino gaming machines has increased in recent years. For example, slot machines historically were mechanical devices (“steppers”) with physical reels that were spun by pulling a lever on the side of the machine. Today, however, mechanical reels in slot machines are typically controlled electronically. The reels can be spun by pushing a button that activates the electronic control, although some machines may retain the traditional lever for entertainment value. In newer video slot machines, the physical reels are replaced by virtual reels whose symbols are displayed on a video screen, controlled by one or more computer processors. These video slot machines typically afford the game designer and operator greater flexibility in customizing the presentation of the game for the operator or the player.
Three-dimensional displays facilitate three-dimensional visualization of a displayed environment by providing visual information that may be used to understand the three-dimensional attributes of the environment, including some visual information not provided by a conventional, two-dimensional image of the environment. For example, a 2D image of an environment does not permit a viewer to see different views of the environment from each eye (“stereo parallax”) or to see different views of the environment from different viewpoints (“movement parallax”), and therefor hampers a viewer's ability to perceive the environment three-dimensionally. By contrast, a 3D image may provide stereo parallax, such that the viewer's left eye may see a view of the displayed environment from a first viewpoint, and the viewer's right eye may see a view of the displayed environment from a second viewpoint. Some 3D images may provide movement parallax, such that the viewer's eyes may see the displayed environment from different viewpoints as the viewer's head and/or eyes move in relation to the 3D image or in relation to some other point of reference.
Different types of 3D display technology are known, including stereoscopic and true 3D displays. Stereoscopic displays present different 2D views of a displayed environment to the viewer's left and right eyes, thereby providing the viewer with stereo parallax information about the environment. Some stereoscopic displays require the viewer to use eyewear (e.g., shutter glasses, polarization glasses, etc.) adapted to present one view of the displayed environment to the viewer's left eye and another view of the displayed environment to the viewer's right eye. By contrast, autostereoscopic displays present different views of an environment to the viewer's left and right eyes without requiring the viewer to use eyewear. For example, an autostereoscopic display may use a parallax barrier or a lenticular lens to divide the display's pixels into a first set of pixels visible to the viewer's left eye and a second set of pixels visible to the viewer's right eye, with the first set of pixels displaying a view of an environment from a first viewpoint, and the second set of pixels displaying a view of the environment from a second viewpoint. Some autostereoscopic displays use head-tracking and/or eye-tracking to locate the viewer's head and/or eyes and to adjust the display so that the views of the environment are continually directed to the viewer's eyes even as the viewer's head moves. An overview of autostereoscopic display technology is given by N. A. Dodgson in Autostereoscopic 3D Displays, IEEE Computer (August 2005), pp. 31-36.
In contrast to stereoscopic displays, which use 2D images to generate stereo parallax, true 3D displays actually display an image in three full dimensions. Examples of true 3D display technology include holographic displays, volumetric displays, integral imaging arrays, and compressive light field displays.